<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>v-if</title>
</head>
<body>
<div id="app">
    <input v-model="score" />
    <h3 v-if="score >= 90">优秀</h3>
    <h3 v-else-if="score >= 80 && score < 90">良好</h3>
    <h3 v-else-if="score >= 70 && score < 80">中等</h3>
    <h3 v-else-if="score >= 60 && score < 70">及格</h3>
    <h3 v-else>不及格</h3>
</div>
<script src="../js/vue.js" ></script>
<script>
    const app = new Vue({
        el: '#app',
        data: {
            score: 90
        }
    })
</script>
</body>
</html>